The invention lies within the area of screwing caps onto containers like bottles and similar types. It relates more particularly to a friction screwing head controlled by twisting torque for installing caps. Among the screwing heads usually used in the bottling industry those provided with a friction clutch can be mentioned in particular. The major drawback of this type of clutch lies in the fact that the application torques achieved for installing the cap are not constant, owing either to the head heating up during operation or to the environmental influences in the presence of nuisances like: moisture, steam, liquid splashing and others of similar type.